Prosthetic Rehabilitation of a Maxillofacial Defect with Silicone Orbital Prosthesis: A Simplified Technique.

Rehabilitation of various maxillofacial defects is a time-consuming, complex, and overwhelming task requiring a patient-specific design and technique. Human face disfigurement involving loss of an eye enhances physical and emotional challenges. A wide range of various treatment modalities are being practiced over the period of time, with the recent one being use of ocular implants. Undoubtedly, an implant-supported orbital prosthesis has a superior outcome; it may not be as practical option considering the cost and availability, especially in economically constrained patients. The present case report describes a simplified technique for fabrication of an adhesive-retained silicone orbital prosthesis. Copyright:

INTRODUCTION

“It is the God given right of every human being to appear human.” – Ernest L. DaBreo

Eyes are generally the first feature of the face to be noticed in a human being. It is considered as a vital organ not only in terms of vision, but also being an important component governing facial expression. Loss of an eye has a tremendous psychological effect on a person. Hence, a prosthetic replacement must be planned and executed at the earliest for the psychological well-being of the patient. If we consider the etiological factors, it is seen that most common tumors that affect the ocular cavity are basal cell carcinoma (BCC), retinoblastoma (RB), and/or squamous cell carcinoma (SSC) of the conjunctiva, which may require partial or complete resection of the eyeball.[1]

Removal of this vital organ may happen in situation of severe trauma, congenital abnormality or disease as any infection or untreatable painful glaucoma.[2]

Various surgical modalities utilized for the removal of an eyeball are classified by Peyman, Saunders, and Goldberg into three general categories: enucleation, evisceration, and exenteration.[3]

Enucleation is a surgical modality involving removal of globe and the attached portion of the optic nerve from the orbit. Evisceration is a surgical modality involving removal of entire contents of the globe, while leaving ocular sclera and extraocular muscles intact. Exenteration is the most radical of the three surgical procedures. It involves surgical removal of the entire eye, adnexa, and part of the bony orbit.[3]

The process involved during making of an orbital prosthesis is full of complexity and an overwhelming journey. It incorporates patient specificity in terms of the technique used. The sole purpose of such prosthesis is to create and restore acceptable anatomical structure and neutralize the lost cosmetic value in a person. Orbital prostheses are generally constructed after complete ocular bed healing (2–4 months time-lapse).[4]

Any facial prostheses can be categorized as successful if it is durable; shows biocompatibility; has acceptable flexibility, color match for realism, and light weight; is hygienic, easily available and easily used by the patient; and is low on maintenance.

Although till date none of the maxillofacial materials available show all these ideal properties, several materials are available that possess most of these properties including increased tear resistance and tensile strength with significant amount of durability. At present, maxillofacial prosthesis for an orbital defect can be made from a variety of materials such as polymethyl methacrylate, polyurethane elastomer, silicone elastomer, or urethane-backed medical-grade silicone.[56]

Among the various historical materials used, silicone elastomeric material emerges out as a widely used material. It is color stable.

LITERATURE REVIEW

Prosthetic replacement of a lost eye is a challenging scenario. It must satisfy certain basic requirements for its success and longevity, as elaborated by Goel and Kumar in 1969.[7]

The use of surgical enucleation hampers orbital growth, as reported by Nath and Gogi in 1976.[8] This may create additional challenges to a maxillofacial prosthodontist.

To retain silicone orbital prostheses, there are different mechanisms like use of natural anatomical undercuts, silicone adhesives, or spectacles.[9] More recently, sabarium magnetic assembly[10] or osseointegrated extraoral implants have been used.[11]

The present case report highlights a simple and economical technique to rehabilitate a patient with silicone-based orbital prosthesis.

CASE REPORT

A 38-year-old female patient reported to the Department of Prosthodontics, Career Post Graduate Institute of Dental Sciences and Hospital, Lucknow with the chief complaint of missing right eye for 23 years (childhood injury). Surgical nucleation of the right eye was performed due to some fungal infection [Figure 1].

Figure 1

Pretreatment photograph – without prefabricated stock eye

Extraoral examination of the patient showed a large orbital defect on the right side [Figure 2]. A definite bony undercut was noticed on the superior border of the orbit, which may eventually help in future retention of the orbital prosthesis.

Figure 2

Pretreatment photograph – with prefabricated stock eye

Recording the Impressions

The patient was properly draped for the impression procedure, and her eyebrows and eyelashes were adequately lubricated with petroleum jelly to facilitate easy removal of the impression material, minimizing patient discomfort. Impression of the orbital defect was made using irreversible hydrocolloid (Zelgan, Dentsply India Ltd.)[1213] backed with a thick coating of dental plaster [Figure 3]. Facial model was poured in dental stone for surface details and strength.

Figure 3

Primary impression with irreversible hydrocolloid

Custom orbital tray was fabricated and definitive impressions were made with addition silicone elastomeric material using putty reline impression technique (Aquasil, 3M Germany) [Figure 4].

Figure 4

Definitive impressions with addition silicone with putty reline technique

Fabrication of Sculpted Clay Orbital Prosthesis

Linear measurements were made from patient's facial midline to the center of the natural pupil, inner and outer canthus of the natural eye for mediolateral eyeball positioning. These linear measurements were made making the patient to look and fix the contralateral eye at distant gaze.[14] Horizontal lines were drawn parallel to the floor passing through inner and outer canthus and were extended to the defect side for superior–inferior positioning of the eyeball. These measurements were transferred on the clay-sculpted prosthesis to help in proper positioning of the ocular portion of the orbital prosthesis [Figure 5].

Figure 5

Sculpted clay orbital prosthesis

Fabrication of Silicone Orbital Prosthesis

The clay-sculpted right eye prosthesis was tried on the patient's face to check for proper orientation of pupil, color match, size, and volume of sclera visible, compared to the contralateral side natural eye. The antero-posterior position was adjusted and verified on the patient [Figure 6]. The wax-sculpted prosthesis with the duplicated cast was flasked and properly dewaxed.

Figure 6

Try-in of sculpted clay orbital prosthesis

For manipulating room temperature vulcanizing (RTV) silicone, manufacturer's instructions were followed. Pigment stains were blended into the base color of silicone material for intrinsic staining during the time of mix to achieve acceptable color match realistic silicone shade as per the patient's facial skin[14] [Figure 7].

Figure 7

Shade selection

Following laboratory polymerization, the prosthesis was deflasked, delicately retrieved, and finished using silicone polishing kit. Natural hair was stitched over the eyebrow area and upper, lower eyelids of the silicone prosthesis using 23-gauge syringe needle [Figure 8]. The eyeglass frame was selected with patient consent and tried on the patient's face [Figure 9].

Figure 8

Application of eyebrow and eyelashes

Figure 9

Definitive orbital prosthesis

Repeated home care instructions were given to the patient and also to a responsible family member. Frequent follow-up sessions were carried out to evaluate orbital prosthesis usage and care. The patient was satisfied with the esthetic outcome provided by the orbital prosthesis. It made her socially presentable thankfully.

DISCUSSION

Over the years, traumatically lost or congenitally missing human eye has been replaced with stock or custom-made prosthesis for years. A custom-made ocular/orbital prosthesis provides a more precise and satisfactory esthetic appearance.

Adhesive-retained silicone orbital prostheses are more practical, trouble free, and cost-effective. The surgery involved during management of such patients put financial burden on the patient. Usually, such patients need economical treatment modality.

If there is a patient suffering from any facial defect, the corrective surgery can lead to disfigurement, presenting a challenge to surgeon and treating maxillofacial prosthodontist. In such a situation, to achieve an acceptable aesthetic outcome is a big task. Hence, specialized professionals working in a multidisciplinary team make such rehabilitations possible with satisfactory results.

Maxillofacial rehabilitation following surgery also needs reconstruction of personality, self-image, and feeling of having overcome the disease. These individual experiences are complex, challenging, and have striking effects on the patients' lives.[15]

The present case report created a cosmetic and social concern, which was successfully treated by an adhesive-retained silicone orbital prosthesis that is practical, trouble free, and cost-effective.

For the past 50 years, these silicone materials have been used in dentistry for prosthetic needs. Silicones possess desirable material properties including biocompatibility, flexibility, ability to accept intrinsic and extrinsic pigments, chemical and physical inertness, and moldability.

Due to better marginal adaptation and life-like appearance, silicone material has been used in the present case report in agreement with Beumer et al.[9]

The patient treated in this case report had a favorable anatomical undercut in the defect site, which enhanced the retention of adhesive-retained silicone orbital prosthesis. The silicone prosthesis has advantages of being light weight and providing better esthetics with life-like appearance than acrylic prosthesis. The thin flash of the silicone eye merged with the adjacent skin to give a life-like appearance.

In the case presented here, the amount of silicone adhesive used was minimal due to the presence of sufficient amount of anatomical undercut. This additional retentive feature ultimately helps in reducing the occurrence of any related allergic reaction that may occur due to long-time adhesive use. For natural effect in artificial eye, artificial hair has being used in the past utilizing readymade eye lashes.

In the present case report, natural hair was stitched in the silicone Prosthesis over the missing eyebrow area and in the upper–lower eyelids using micro sized suture needle. In the inner canthus of eyeball, pink acrylic resin was added to mimic natural eye and camouflage effect.

In the case presented here, for symmetry, linear measurements were used in agreement with Supriya and Ghadiali[14] for the fabrication of orbital prostheses.

In 2006, Artopoulou et al.[16] demonstrated the use of digital photographic imaging to replicate natural eye position on the missing side.

CONCLUSION

In the event of surgical enucleation of orbital contents, the involved person's life is changed as it impacts esthetic value, impairs functionality, and, above all, leads to irreparable psychological trauma. In such a scenario, a prosthetic replacement that is well retentive in place acts as a game changer. Such prosthesis must be user-friendly for a successful rehabilitation.

As dental professionals, it is our duty to implement our knowledge into practicality and fabricate the prosthesis in an acceptable fashion to meet the physiologic, anatomic, functional, and cosmetic requirements of the patient. It may boost the patients' confidence and motivate them to lead a better life. Although the patient cannot see by this prosthesis, it increases the self-confidence of the patient to face the world. However, marginal breakdown and discoloration are common problems associated with these silicone-based prostheses, necessitating their refabrication and warranting more research and advancement in material science.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.